The subject matter described herein relates generally to imaging systems, and more particularly, to a methods and devices for reducing leakage currents in an imaging system detector
Radiation detectors may be used in a wide variety of applications. For example, radiation detectors may be used in medical imaging systems to capture images of objects. The captured images may diagnostic images of a person or an animal which are then used by a doctor or other health care professional in making a diagnosis. Radiation detectors may also be used to image luggage, shipping containers, as well as for industrial inspection. Radiation detectors also may be used for non-imaging applications, such as for security detection and identification of radionuclides. In these non-imaging applications, the spectral response for the radiation detectors is used.
The radiation detectors may be, for example, pixelated radiation detectors, such as Cadmium Zinc Telluride (CZT) detectors, which are increasingly used. In these systems, the signal levels (e.g., the amount of signal generated by an x-ray or Gamma event) from the detector are often extremely small and easily corrupted by digital activity within the system. For example, the digital communication links within the system can generate noise that interferes with the signals from the detectors. However, signals are needed for controlling the system, such as the state of the system, transitions between different operations, etc., for example, during data acquisition.
In general, CZT detectors are fabricated using a large quantity of components that are closely spaced to each other to enable a plurality of CZT detectors to be positioned on a single board. As such, the various components used to fabricate the CZT detector are generally spaced relatively closely to each other. Moreover, at least one known CZT detector operates using approximately 600 volts that is supplied to the CZT detector using a high voltage (HV) connector.
However, in some operating conditions, humidity may form between one or more components in the CZT detector. As one example, humidity may form between the HV strip and other components. The humidity, e.g. moisture, may therefore reduce the electrical isolation between the HV connector and the other components. More specifically, the humidity may cause leakage currents or crosstalk signals to be generated in the CZT detector. As a result, the CZT detector may generate false events or false hits to be generated. Moreover, because true and false hits cannot be distinguished after detection, these false hits are not accounted for in the subsequent signal processing. These incorrect counts (e.g., an incorrect number of photon counts) that are added to the relevant energies may cause significant image artifacts, thereby decreasing image quality and reducing the reliability of image acquisition results and any analysis of these images thereafter.